Petrified Wood
Silicified Wood / Petrified Wood (Quartz var. Chalcedony/Jasper) · Mineral Specimen and Decorative Stone
Crystal System
Trigonal (Cryptocrystalline microfibrous quartz structure)
Mineral Group
Silicates (Tectosilicate subgroup)
Chemical Formula
SiO2 (Silicon Dioxide with various trace minerals like iron, carbon, and manganese oxides)
Formation Process
Sedimentary/Permineralization process where organic material is buried in anoxic, mineral-rich sediment and gradually replaced by silica over millions of years.
About This Crystal
Elongated, rough, brownish-orange log fragment displaying preserved structural wood grain texture, concentric growth lines, earthy luster, and complete opacity.
Physical Characteristics
Brown to reddish-orange body color with a white streak, uneven to conchoidal fracture, no true cleavage, specific gravity of approximately 2.55 to 2.70, and brittle tenacity.
Optical Properties
Singly refractive aggregate (microcrystalline), typically non-pleochroic, with a refractive index around 1.530 to 1.540.
Hardness & Durability
Origin Region
Found globally; notable locations include Petrified Forest National Park in Arizona, USA, Madagascar, Argentina, and Australia. Forms in sedimentary environments with volcanic ash or silica-rich waters.
Hardness & Durability
Mohs hardness of 6.5 to 7, making it quite durable and suitable for cabochons and decorative carvings, comparable to quartz.
Care & Maintenance
Clean with warm soapy water and a soft brush, store away from direct sunlight and harder minerals to prevent scratching, highly resistant to common household chemicals.
Rarity & Value
Common, though exceptional specimens with vibrant color replacements or complete log sections can be quite valuable. Treatments are generally not needed as natural specimens are abundant.
Special Characteristics
Preserved cellular structure of ancient trees, sometimes featuring chatoyancy or colorful mineral inclusions like iron oxides and jasper.
Lore & History
Historically used for decorative artifacts and talismans. In crystal healing lore, it is associated with grounding, patience, transformation, and stability, though these are traditional beliefs.